We had a great trip to the caves with young kids in tow. The trip down through natural bush is lovely, though is all downhill and was a little worried about the return leg. We got to the beach right on low tide (walk is only open 2 hours either side of low tide so check before you go) so could get into the cave without getting wet. Be prepared to get a bit wet though if you aren't right on the low tide. Surprised how beautiful and golden beach was. The return walk was easier than expected and the kids made it up without any trouble. Took us about 1.5 hours including time exploring the cave and beaches. Highly recommend this walk.
Probably should mention that there is a charge for use of the track ($5 adults, $1 kids).